Mineralization reactions and CO₂ storage

Mineral carbonation captures and stores carbon dioxide by converting it into stable carbonates. This process mimics natural mineral reactions, where CO₂ reacts with calcium or magnesium containing minerals over long time periods to produce stable compounds such as calcite (CaCO₃) or magnesite (MgCO₃).

Typical reactions include:

CaSiO₃ + CO₂ → CaCO₃ + SiO₂

Mg₂SiO₄ + 2CO₂ → 2MgCO₃ + SiO₂

These reactions are thermodynamically favourable, meaning they convert CO₂ into products that are more stable and exist at a lower energy state than the gas phase.

To make this process practical at an industrial scale, it is carried out under controlled temperature and pressure conditions to speed up the reaction. Efficiency can be further improved through specific pre-treatment steps:

·Mechanical activation: grinding the minerals into a fine powder, to exponentially increase the reactive surface area allowing CO₂ to react more easily.

· Thermal activation: applying heat to disrupt the crystalline structure of the minerals, making the calcium and magnesium ions more accessible for the reaction.

Suitable materials for mineral carbonation include calcium and magnesium based compounds such as calcium oxide, magnesium oxide and silicate minerals. In addition to natural minerals, industrial residues such as steel slag, fly ash or cement waste can also be used as feedstock. These materials are widely available and can be sourced from existing industrial processes, which makes mineral carbonation an attractive option for integrating carbon capture with waste valorisation.

Beyond storage, captured CO₂ can also serve as a raw material in industrial processes. It can be used to produce chemicals and materials such as urea, methanol, polymers and precipitated calcium carbonate.

Although mineral carbonation still faces challenges related to reaction speed, energy use and process cost, it remains attractive because it offers permanent CO₂ storage and relies on widely available materials.

At CymitQuimica, laboratories working on mineral carbonation and CO₂ utilisation can find products for material development, testing and analysis.

Our team can assist in identifying the most suitable products for each application. For more information, contact our customer support team at support@cymitquimica.com.